Importing a VM from an Export domain fails with "No space left on device"

Issue

• Importing a VM from an Export storage domain fails.

• Error reported in the vdsm logs on the SPM host;

Error: Command ['/usr/bin/taskset', '--cpu-list', '0-55', '/usr/bin/nice', '-n', '19', '/usr/bin/ionice', '-c', '3', '/usr/bin/qemu-img', 'convert', '-p', '-t', 'none', '-T', 'none', '-f', 'qcow2', 
u'/rhev/data-center/mnt/server-a:_export_sd/acc53a18-e2e9-48a1-9b37-b8b0f2e5ad01/images/4fbb944f-26cc-4767-92e4-db52ad60fc06/31284701-2a00-41ae-acd2-41c3bbb468d8', '-O', 'qcow2', '-o', 'compat=1.1',
 u'/rhev/data-center/mnt/blockSD/535d1915-2469-4847-a9e1-9966c00f0a25/images/4fbb944f-26cc-4767-92e4-db52ad60fc06/31284701-2a00-41ae-acd2-41c3bbb468d8'] failed with rc=1 out='' err=bytearray(b'qemu-img: error while writing sector 346177536: No space left on device\n')